This application relates to a tooth profile for a clutch design wherein a separating force is reduced due to selected angles on the teeth.
Clutches are utilized in many applications to selectively transmit rotation from a drive shaft to a driven shaft. Clutches have teeth that engage each other, and which transmit torque during rotation. Typically, one of two clutch members is moved axially away from the other to disengage the clutch. This movement may occur while torque is still being transmitted between the teeth, and thus there is sometimes a challenge in separating the two.
In known art, the mating faces of the clutch teeth have a negative rake angle that has been relatively large, e.g. 5°, for example. This angle causes the clutch teeth to hook and lock the two halves of the clutch together while torque is being applied.
The clutch decoupling occurs while this torque is being transmitted. Thus, there is a significant amount of additional torque required to impart an angular twist onto one of the shafts to overcome the negative rake angle on the jaw teeth clutch. This additional torque (spike) is directly imparted to the gearbox that drives the generator, which necessitates that its gear train components be robustly designed to handle this additional torque loading. As the jaws are eventually separated through the negative rake portion of the tooth profile, a chamfered end of the tooth profile can also raise challenges since it is at a relatively small angle, 45° for example.
Potential energy may be stored in one of the two shaft members during wind-up, and may be released as a launching force that axially translates the movable jaw clutch member to a decoupled position. This force can impart an axial load to the input shaft and its support bearing.
Currently, such generators are often utilized in aircraft applications. In aircraft applications, these generators are exposed to very high speeds of rotation, and on the order of 16,000 rpm. Under such high speeds, there are significant challenges from the issues mentioned above.